SAR image with black borders after processing

Hi everyone,
after processing SLC images, my final products have some borders with a 0 value (painted black). Does anyone know the reason of this? Is it possible to correct this error?


Impossible to say due to lack of information, see: FAQ - STEP Forum (

I’m sorry, I didn’t specify the processing steps because this happens a lot with different processings. For instance, these are two assembled SLC products, splitted, orbit applied, calibrated, debursted, speckle-filtered using polarimetric speckle filtering, and terrain corrected. Before Terrain Correction, I have created this filtered band using morphological features (closing 3x3). Thanks.

It should be possible to correct that in post-processing, the 0 values are simply areas with No Data. It gets a bit more tricky if you have valid pixel values that are also zero. There should be people on this forum that can give you more detailed processing advice.

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Some processing produces values for a target pixel using data from neighbouring pixels. If the target pixel is to close to the edge, some neighbouring pixels will not have data. Depending on the algorthm and implementation, this can cause the target pixel to be assigned a no-data value.